Final answer:
The bond angles around carbon in C2Ic vary depending on the hybridization of the carbon atoms. Carbon 1 and carbon 2 have bond angles of 180 degrees, carbon 3 and carbon 4 have bond angles of 120 degrees, and carbon 5 has a bond angle of 109.5 degrees.
Step-by-step explanation:
The ideal bond angles around carbon in C2Ic can vary depending on the hybridization of the carbon atoms. In this molecule, carbon 1 and carbon 2 are sp hybridized and have bond angles of 180 degrees. Carbon 3 and carbon 4 are sp2 hybridized and have bond angles of 120 degrees. Carbon 5 is sp3 hybridized and has a bond angle of 109.5 degrees. Therefore, the correct answer is d) 109.5 degrees.